Party-line ringing system.



G. S. WINSTON.

PARTY LINE RINGING- SYSTEM.

APPLICATION FILED SEPT.16, 1908.

Patented May 23, 1911.

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UNITED STATES PATENT OFFICE. 1

CHARLES S. WINSTON, OF CHICAGO, ILLINOI, ASSIGNOR TO KELLOGG- SWITGI-IBOARD AND SUPPLY COMPANY, OF CHICAGO, ILLINOIS, A CORPORATION OF ILLINOIS.

Specification of Letters Patent.

Patented. May 23, '1911.

Application filed September 16, 1908. Serial No. 453,276.

To all whom it may concern;

Be it known that I, CHARLES S. WINSTON, a citizen of the United States, residing in Chicago, county of Cook, and State of Illinois, have invented certain new and useful Improvements in Party-Line Ringing Systems, of which the following is a specifica tion.

My invention relates to telephone systems,

and particularly to the circuit arrangement and ringing \key at the central office of a party line telephone system.

The objectof my invention is to provide a ringing system in which a plurality of ringing key contacts are associated with the ringing key but excluded from the talking circuit during conversation. I

My invention is illustrated in the accompanying drawing inwhich all of the apparatus is shown in its normal or unactuated condition.

The calling subscribers station 1 is equipped with the usual condenser 2 and annunciator 3 in a bridge between the line conductors 4 and 5, and with the transmitter 6 and receiver 7 in a bridge maintained normally open by contacts of the switch hook 8. At the central office, line conductor 4 is connected through contacts 9 and 10 of cutoff relay 11 and through the coil of line relay 12'and conductor 13 with the live pole of battery 14, and conductor 5 is connected with earth through contacts 15 and 16 of cut-off relay 11. Cut-ofl relay 11 also has the normally disconnected inside contacts 17 and 18, contact 17 being connected through the coil of relay 11 with earth, and alsowith the sleeve contacts 20 of the answering and multiple jacks. Contact 18 is connected with the tip contacts 21 of the answering and multiple jacks. The line relay 12 controls normally open contacts 22 and 23 in the cir-' cuit of the line lamp 24.

The answering subscribers line is here shown equipped with four stations, these stations being provided with selective annunciators by means of which any one of the subscribers stations may be selectively called. The apparatus associated with this line is similar to the apparatus associated with the calling telephone line, the corresponding apparatus being designated by like figureswith the suflix The cord circuit to connect the calling andanswering lines for conversation is of the well known four relay type and extends in two talking strands from the tip 25 of the answering plug through conductor 26,

condenser 27, conductor 28 and conductor 29 to the tip contact 30 of the calling plug and from the sleeve contact 31 of the answering plug through conductor 32, condenser 33, conductor 34, and auxiliary contacts 35 and 36 of the ringing key 37 to the sleeve contact 38 of the calling plug. The tip and relay 44 has the normally open contacts 46' and 47, maintaining a normal break'between tip conductors 28 and 29 and has the normally closed contacts 48 and 49, the consleeve answering supervisory relays 40 and tact 48 being connected through conductor 50 with the last series contact of the ringing key 37, and the contact 49'being connected through conductor 51 with the normally open auxiliary contact 52 of the operators listening key 53; The other normally open auxiliary contact 54 of this key is connected with earth through the impedance 55, and with battery through the condenser 56 and the tertiary winding of the operators in-' duction coil 57. The first spring contact of the operators ringing key is connected directly with the tip conductor 29; The normally disconnected auxiliary contact 60 of I the operators ringing key is connected through the non-inductive resistance 61- with the live pole of battery 14. In the operation ofthis system, the subscriber in charge of substation 1 removes his receiver 7 from the switch hook 8, thus closing the circuit from the live pole of battery 14 through conductor 13, the coil of line relay 12, contacts 10 and 9 of cut-01f relay 11, line conductor 4, transmitter 6, re- 7 I ceiver 7, contacts of switch hook 8, line conductor 5, and contacts 15 and 16 of cut-oft relay 11 to earth. The current in this path actuates line relay 12 closing its contacts 22 and 23 and causing the display of the line lamp 24. The operator upon observing the display of the signal 24 inserts her answering plug into the answering jack thus designated and thereby completes a circuit from the live pole of battery 14 through the coil of supervisory relay 41, conductor 32, sleeve contacts 31 and 20 of the answering plug and jack and the coil of cut-off relay 11 to ground. The current in this path actuates cut-oft relay 11 moving its contacts to their abnormal positions and severing the circuit of the line relay 12 which inturn etliaces the line signal 24. A further circuit is thereby completed through contacts 17 and 9 of cut-0E relay 11, over line conductor 4, transmitter 6, receiver 7, contacts of switch hook 8, line conductor 5, contacts 15 and 18 of cut-0H relay 11, tip contacts 21 and 25 of the answering jack and plug, tip conductor 26 and the coil of supervisory relay 40 to ground. The current in this path also actuates relays 40 and 41, the actuation of relay 41 closing the circuit of supervisory signal 42 and the actuation of relay 40 opening the circuit of this signal, whereby the signal remains in its effaced condition. The operator now actuates her listening key 53 and'inquires the desired number. Finding this to be that of one of the parties upon the telephone line 1, the operator touches the tip 30 of her calling plug to one of the multiple contacts '20 of the desired line. If this desired line is busy another cord circuit will be connected with the line and the sleeve contacts will therefore be maintained at a potential higher than that of earth. Current will therefore flow over the tip of the plug, through the series contact of the ringing key 37, conductor 50, contacts 52 and 54 of the operators listening key 53 to earth through the impedance coil 55. The flow of current in this path will cause a slight discharge of the condenser 56 and a consequent current through the tertiary winding of the operators induction coil 57. This disturbance will be inductively reproduced in the operators receiver circuit, thus indicating to the operator that the desired line is busy. Assuming, however, that the desired line is found idle, and that no click is heard by the operator, the calling plug is inserted completely into the jack of the desired line, and the ringing key adapted to connect the current of the proper character on to the telephone line for selecting the desired party, is actuated. Upon the actuation of any one of the ringing keys the auxiliary contacts associated with the key are also actuated and a circuit is thereby coinpleted from the live pole of battery 14 through the non-inductive resistance 61, auxiliary contacts 60 and 36 of the operators ringing key, sleeve contacts 38 and 20 of the calling plug and jack, and the coil of cut-off relay 11 to ground. The current in this path actuates relay 11 moving its contacts to their abnormal positions and connecting the limbs 4 and 5 of the telephone line directly with the contacts 20 and 21 of the multiple jacks. The current from one of the calling generators is thus sent through its associated ringing key, the tip contacts 30 and 21 of the plug and jack, contacts 18 and 15 of cut-off relay 11, line conductor 5, the annunciators 3 and condensers 2, line conductor 4, contacts 9 and 17 of cutolf relay 11, contacts 20 and 38 of the jack and plug, auxiliary contacts 36 and 60 of the ringing key 37, non-inductive resistance 61, the battery 14, and through earth back to the ground pole of the generator. This current being fluctuating in character, passes through the condensers 2 and selectively operates the annunciator characterized to respond to the distinctive current sent upon the line. Upon the release of the ringing key, the auxiliary contacts resume their normal positions and a circuit is completed from the live pole of battery 14 through the coil of supervisory relay 44, conductor 34, auxiliary contacts 35 and 36 of the ringing key 37, sleeve contacts 38 and 20 of the plug and jack and the coil of out-ofi relay 11 to ground. Gurrent in this path maintains the actuation of the cut-off relay 11 and actuates supervisory relay 44. The actuation of supervisory relay 44 completes the circuit of supervisory signal 45, displaying that signal to indicate to the operator that the called subscriber has not yet answered his call. The actuation of relay 44 also closes contacts 46 and 47 completing the circuit between the portions 28 and 29 of the tip talking conductor, and also opens contacts 48 and 49 which severs the testing circuit so that the actuation of the listening key will not again connect the testing apparatus with a talking strand of the cord circuit.

hen the called subscriber answers his call a further circuit is completed through con tacts 17 and 9 of cut-off relay 11, line conductor 4, transmitter 6, receiver 7, and switch hook 8 of the answering subscribers station line conductor 5 contacts 15 and scribers' are now in condition for conversation and all signals are effected at the cenremoves her answering and calling plugs from their respective jacks and thus severs the circuit of cut-off relays l1 and 11, and of supervisory relays 41 and 44. When these relays resume their normal positions the supervisory signals 42 and 45 are again etfaced and all of the apparatus has assumed its original and normal condition.

It will be observed that during the testing of an idle line the tip talking strand is interrupted at contacts 46 and 47 of supervisory relay 44, whereby none of the testing current is shunted away from the test receiving apparatus, and also that during ringing these contacts 46 and 47 still maintain the interruption of the tip strand so that the ringing current does not pass, back to the calling subscriber or through the coils of the supervisory relays associated with the tip side of the trunk circuit. It will further be observed that during the use of the cord circuit relay 44 is actuated closing the normal interruption in the tip talking strand and disconnecting the testing apparatus so that the use of the listening key will not disturb the balanced condition of the system during conversation. It will further be noted that the auxiliary spring contact 36 of the ringing key 37 is preferably'mechanically connected with all of the other contacts of the key, whereby it is actuated simultaneously with or preferably slightly before the complete actuation of the ringing circuit contacts.

While my invention has been here shown and described in connection with a specific form of telephone system, it is to be understood that it is applicable to many different forms of telephone systems, and while my invention itself is here illustrated in a specific form, it is to be understood that I do not wish to be unduly limited thereto, certain modifications being possible without in any way departing from the spirit or scope of my invention.

I claim:

1. In a telephone system, the combination with a cord circuit, of a ringing key permanently connected with a contact of the calling plug of said circuit, a supervisory relay actuated over another strand of said cord circuit, a test receiving device normally conand through series contacts of said ringing key, said supervisory relay having normally open contacts in the circuit of the tip strand of the cord circuit, the actuation of the ringing key being adapted to de'elnergize said supervisory relay, whereby ringing current will not pass to the calling subscribers line, said supervisory relay being actuated during conversation to disconnect the test receiving device, substantially as described.

2. In a telephone system, the combination with an'operators connect-ing circuit of a tip calling strand therefor, branch conductors leading therefrom, one conductor being normally interrupted at the contacts of the sleeve calling supervisory relay, the other conductor containing series contacts in the operators ringing key, normally closed contacts of said supervisory relay, normally opencontacts associated with the operators listening key and a test receiving device, substantially as described. v

3. In a telephone system, the combination with a cord circuit, of a testing contact therefor, branch conductors leading therefrom, a supervisory relay, a ringing key, one conductor containing series contacts of said ringing key and normally closed contacts of said supervisory relay and a test receiving device, and the other conductor containing normally open contacts of the said supervisory relay, substantially as described.

4. In a telephone system, the combination with a cord circuit of a. ringing key associated with said cord circuit and having series contacts, a test conductor normally completed through the series contacts of said ringing key, a talking strand directly connected with a tip of the calling plug, said strand being interrupted during ringing to prevent ringing current from passing to the calling subscribers line, the series contact-s of said ringing key being permanently connected with the talking strands of said cord circuit but removed from the talking circuit, substantially as described.

5. In a telephone system, the combination with thecord circuit having tip and sleeve. talking strands, a supervisory relay and a ringing key for said cord circuit, a test receiving device adapted to be connected with the tip of the calling plug for testing through contacts of said supervisory relay and series contacts of said ringing key, the tip strand of the cord circuit being nor- Inally interrupted at cont-acts of saidsupervisory relay and being connected with the tip of the calling plug ahead of the first series contact of the ringing key, whereby the talking current will not pass through the series cont-acts of the ringing key, substantially as described. v

6. In a telephone system, the combination with a cord circuit, of a normally open talking conductor connecting the ends of said cord circuit, a ringing key having series con- Signed by me at Chicago, county of Cook, tacts, one of Which is permanently connected and State of Illino1s, 1n the presence of two to said conductor between break and the call- Witnesses.

ing end of said cord circuit, said series con- CHARLES S. WVINSTON. tacts being removed from the talking circuit, WVitnesses:

and means for establishing the continuity of CLIFFORD C. BRADBURY,

the said talking conductor aft-er ringing. MARJORIE E. GRIER.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents, Washington, I). 0. 

